Optical coupler

Abstract

An optical coupler including: a substrate; a cladding layer formed on the substrate; and a slab waveguide formed on the cladding layer, wherein the slab waveguide comprises a first waveguide area on which a laser beam is incident and a second waveguide area having an incident surface capable of converging and outputting the laser beam passing through the first waveguide in a width direction. The optical coupler may optically couple one of an optical fiber and a laser diode with the slab waveguide, and more particularly, and a photonic crystal waveguide, with high efficiency.

1. An optical coupler comprising:
 a substrate; 
 a cladding layer formed on the substrate; 
 a slab waveguide formed on the cladding layer; and 
 an optical converter converting and outputting the incident light into a plane laser beam and allowing the plane laser beam to be incident on the slab waveguide, 
 wherein the slab waveguide comprises a first waveguide area on which a laser beam is incident and a second waveguide area having an incident surface capable of converging and outputting the laser beam passing through the first waveguide area in a width direction. 
 
     
     
       2. The optical coupler of  claim 1 , wherein the first waveguide area and the second waveguide area are integrated into one body. 
     
     
       3. The optical coupler of  claim 2 , wherein the laser beam passing through the second waveguide area is incident on a waveguide of an output terminal connected to the second waveguide area, and
 the slab waveguide and the waveguide of the output terminal are integrated into one body. 
 
     
     
       4. The optical coupler of  claim 1 , further comprising a reflection mirror reflecting a laser beam that is not incident on the slab waveguide among the laser beam passing through the optical converter, to be turned toward the slab waveguide. 
     
     
       5. The optical coupler of  claim 1 , wherein the laser beam incident on the optical converter is oscillated from one of a terminal of an optical fiber and a laser diode. 
     
     
       6. The optical coupler of  claim 1 , wherein the optical converter has a lattice structure. 
     
     
       7. The optical coupler of  claim 6 , wherein the optical converter converts a laser beam longitudinally incident from the top into the plane laser beam and outputting the plane laser beam in a lateral direction. 
     
     
       8. The optical coupler of  claim 1 , wherein the first waveguide area and the second waveguide area are integrated into one body. 
     
     
       9. The optical coupler of  claim 8 , wherein the slab waveguide and the optical converter are integrated into one body. 
     
     
       10. The optical coupler of  claim 9 , wherein the laser beam passing through the second waveguide area is incident on the waveguide of the output terminal connected to the second waveguide area, and
 the slab waveguide, the optical converter, and the waveguide of the output terminal are integrated into one body. 
 
     
     
       11. The optical coupler of  claim 1 , wherein the laser beam passing through the second waveguide area is incident on the waveguide of the output terminal, and
 a waveguide of an output terminal is a photonic crystal. 
 
     
     
       12. The optical coupler of  claim 1 , wherein the first waveguide area and the second waveguide area are formed of the same material and have a different thickness from each other. 
     
     
       13. The optical coupler of  claim 12 , wherein the second waveguide area has a thickness greater than a thickness of the first waveguide. 
     
     
       14. The optical coupler of  claim 12 , wherein the first waveguide area has a thickness with one to three laser beam modes. 
     
     
       15. The optical coupler of  claim 12 , wherein the second waveguide area has a thickness with one to five laser beam modes. 
     
     
       16. The optical coupler of  claim 1 , wherein the second waveguide area has an effective refractive index greater than an effective refractive index of the first waveguide area. 
     
     
       17. The optical coupler of  claim 1 , wherein the laser beam passing through the second waveguide area is incident on the waveguide of the output terminal connected to the second waveguide area, and
 the second waveguide area and a waveguide of an output terminal have the same thickness. 
 
     
     
       18. An optical coupler comprising:
 a substrate; 
 a cladding layer formed on the substrate; and 
 a slab waveguide formed on the cladding layer, 
 wherein the slab waveguide comprises a first waveguide area on which a laser beam is incident and a second waveguide area having an incident surface capable of converging and outputting the laser beam passing through the first waveguide area in a width direction, and 
 the second waveguide area has a convex-lens shape. 
 
     
     
       19. An optical coupler comprising:
 a substrate; 
 a cladding layer formed on the substrate; and 
 a slab waveguide formed on the cladding layer, 
 wherein the slab waveguide comprises a first waveguide area on which a laser beam is incident and a second waveguide area having an incident surface capable of converging and outputting the laser beam passing through the first waveguide area in a width direction, and 
 a first waveguide area is formed of a different material from the second waveguide area. 
 
     
     
       20. The optical coupler of  claim 19 , wherein a material forming the second waveguide area has a refractive index greater than a refractive index of a material forming the first waveguide area. 
     
     
       21. The optical coupler of  claim 19 , wherein the first waveguide area and the second waveguide area have the same thickness.